A interlocking control has so far been known in which a device (interlocked device) is operated according to a signal indicating an operation of another device (trigger device). The interlocking control is applicable to an air-conditioning system, so as to control operations of air-conditioning apparatuses in linkage with the trigger device (see, for example, Patent Literature 1). Patent Literature 1 discloses, as an example of the interlocking control, a method of turning off all indoor units in a conference room when the conference room is locked, and turning on all the indoor units in the conference room when one of the indoor units in the conference room is turned on.
In addition, an air-conditioning system has been disclosed to which the interlocking control is applied such that a person identification device is employed as the trigger device, and the air-conditioning apparatus is set to a temperature that suits the preference of the person in accordance with the identification result of the trigger device (see, for example, Patent Literature 2).